Process and means for metal depositing



Aprilv 19, 1932. J. B. GRENAGLE 1,854,790

I PROCESS AND MEANS FOR METAL DEPQSITING Filed Jan. 24, 1930 W f INVENTOR.

4 W'ATTORNEY.

Patented Apr. 19, 1932 UNITED STATES PATENT OFFICE JAMES B. GRENAGLE, OF BALTIMORE, MARYLAND, ASSIGNOR OF ONE-BALI TO WILLIAM W. VARNEY, OF BALTIMORE, MARYLAND, AND ONE-HALF TO UNIVERSAL ALLOYS, INCORPORATED, OF BALTIMORE, MARYLAND, A CORPORATION OF MARY- LAND PROCESS AND MEANS FOR METAL DEPOSITING Application filed January 24, 1930. Serial No. 423,017.

g The object of my invention is the depositing or plating of metals.

A further object of my invention is the depositing of alloys of metals on a metal of the same group of which one member of employed, combination and arrangements of systems, apparatus and means as hereinafter specifically provided, but it is understood that changes, variations and modlfications may be resorted to which come within the scope of the claims hereuntoappended.

It is a recognized fact that platlng articles in the ordinary bath does not produce a lasting coating when exposed todisintegratlng elements; for example, chrome plating on steel apparently gives very satisfactory results, but in time pitting or corrosion 1n sp'ots occurs. Likewise, articles plated with nickel on iron show but short life when exposed to weather conditions. I have discovered a new method of depositing metals on other metals in such action as will make the plating permanent.

. I have discovered that using a plating metal, or an alloy of said plating metal alloyed with the metals to be plated disintegrated at the time of plating in a conveying bath and electrically deposited on the article to be plated, forms a kindred congenialv association with ln'ndred or like metals; at the same time, the metal being plated is not, attacked by the conveying solution used, as the plated element is not a chemical component part of said solution unelectrically' energized.

To more fully understand myinvention 1 will first describe the ap aratus used in a small way and a number 0% the solutions used for 'diiferent elements. g

In the drawings of the herein described apparatus embodying features of my invention, and which may be used in the practicing thereof and the production of the product involved, Figure l is a cross-section in elevation taken through 11 of Fig. 2, and shows a preferred desired position of the respective parts involved; but these positions may be varied at will to a very large extent; Fig. 2 is'a plan view of the apparatus shown in Fig. 1. The apparatus I am describing is a lead lined tank of substantially 3 ft. square by about 2 ft. deep. These figures are given simply for illustrative work to convey an impression of the apparatus used.

Similar numerals refer to similar parts throughout theseveral views.

l is a wooden tank lined with lead 2. 3 is a stufiing box in the lower part of the tank for the introduction of an electrode; this stufling box is insulated from the tank by insulation 4:. 5 is a supporting clamp resting upon support 6 and insulated therefrom by insulation 7. 8 is a rod or support resting upon the top of the tank or lead covering, but insulated therefrom by insulation 9 and is itself an electric conductor.

On rod or support 8 are hung the articles 10 to be plated, as shown, an automobile headlight. These are supported by conducting wires 11, or other suitable means; wires for illustrative purposes are much simpler than clamps or rigid supports, which may be used, if desired, at the anode terminal. To these articles 10 a plus terminal 12 is attached of a direct current electrical circuit, as shown in the drawings by means of connecting wires 'These plates are clamped on to carrier 15 by any convenient means, as shown simply hung on the carrier; but it is'pr ferable to have a better contact and that is at ained by clamp ing the plates to lugs on the carrier.

Carrier 15 and its vertical posts 16 are electric conductors which are operated through ing and supported by supporting clamp 5, and are of iron or steel, as an automobile headlight to r be plated with chromium.

The plating metal 14 consists of chrome ferric alloy, preferably plates made of an alloy, of chromium and 30% iron. The negative terminal, or cathode, 13 that I would use in this case would be of iron. The tank is partially filled with a solution of the following; Precipitated 200 grammes of plus 24H O with NH Wash the hydrooxide and dissolve in 120 grammes chromic acid dissolved in 2000 cu. cent. H O. This bath should be preferably maintained at a temperature of 40 C. Current should be used for about forty minutes in the alternating circuit coming from terminal 18, and a slow direct current of about 12 amperes flowat the same time.

have discovered that the direct terminals should be as near the bottom of the tank as practicable; likewise, the articles to be plated, with a considerable depth of the solution above them.

I have d scovered that plating on a metal from a similar metal containing the major metal to be plated forms a very tough amalgamation, if I may use that expression, coat- If it is desired to plate with nickel, plates 14 would be of a pure electrode nickel; if plating upon iron 10, an electrode 13 would also be of iron, and the following solution would be used in the tank:

NiSO4+7H2O grammes, M SO +7H O 15 grammes, H BO 15 grammes, H 0 1000 cu. cent. This bath should be maintained at 20 (3., and the alternating current from terminal 18 should be run twenty minutes and a direct current of 2 amperes for the same length of time.

If plating with cobalt is desired on iron, using an iron. terminal 13, plates 14 should be made of cobalt, and the following solution used in the tank: 7

COSO +H O, 175 grammes, H 0 1000 cu. cent.; the bath should be maintained at a temperature of 15 0., using from two to four amperes direct current between terminals 13 and 10, and alternating current from terparatus and by my process.

minal 18, both currents simultaneously for about 30 minutes.

If it is desired to plate with cadmium on iron 10 with the iron terminal 13, the plates 14 are made of cadmium and the solution in the tank is as follows:

Cd(CO 12 grammes, KGN 35 grammes, H 0 1000 cu. cent. This solution should be maintained at a temperature of 15 C. and a direct current of from 1 to 2 amperes should flow from the terminals 13 to the terminal 10 while an alternating current flows from terminal 18 for 30 minutes.

In the above, I have given four examples of coating on iron with elements in a solution that will not attack the iron.

While I have used iron as illustrated, I do not wish to limit myself to the same, as any conducting metal, or any surface rendered conductive, may be plated upon with my ap- While I have shown the preferable solutions for the various alloys used, it is not necessary that the solution attack in any way the terminals 10 and 13; but, on the contrary, it is very desirable that the solution should not attack these terminals. It is desirable that the solution should attack the plates or elements 14; this, however, is not absolutely essential, as the alternating current does the work at these terminals, and the direct current appears to be the conveying agent. The .alternatin current is controlled as desired by any wel known means; I have shown a resister, 21.

As an illustration, I will plate on copper at terminal 10, using an iron electrode at 13 and chromium ferric as described in the first example iven above for plates 14 and the solution a ove mentioned for chrome plating; the copper will be thoroughly plated, probably not as intimately associated with the plating as the iron would be.' It will be preferable in this example to use a. ferric chrome alloy, and also, preferably, a terminal 13 of copper.

While I have shown and described as a specific example an alternating circuit in which plate 14 is in circuit, a direct current may be used for disintegrating purposes through said plate 14; and while I have shown the lead lining 2-in said circuit, this terminal may be an independent removable terminal.

While I have shown terminal 13 as removable, I can use the tank lining 2 for this terminal.

I do not wish to be limited to any arrangement of the terminals, or to the character of current rsed. 1

Having thus described my invention, what I claim and desire to secure by Letters Patent 1s:

1. An electric plating means consisting of the metal to be plated operated upon by an alternatin current of electricity in circuit with a disintegrating bath for said metal, an

object to be plated in said bath operated upon by a direct current of electricity the circuit of a which comprises said bath, said object to be plated and means for contactin with said bath independent of the circuit 0 said alternating current whereby an element in said bath is deposited on said object.

2. An electric plating means consisting of the metal to be plated operated upon by an alternating current of electricity in circuit with a disintegrating bath for said metal, an object to be plated in said bath operated upon by a direct current of electricity the circuit of I which comprises said bath, said object to be both of said currents operating at the same time but from different terminals respectively.

4. The process of depositing an alloy on an object to be plated consisting of disintegrating the alloy in a disintegrating element thereof, by an alternatin electric current one pole of which consists of the alloy to be disintegrated and the other pole of which comprises a contacting means in said disinte rating element, and then. depositing the dis ntegrated alloy from said disintegrating element on to the object to be plated by electric means independent of the disinte ating means.

J AMES- B. GRENAGLE. 

